You can also look at disk sales numbers, which are a little fuzzy because you have to factor in whether or not Blu-ray/DVD/Laserdisc (depending on the era) sales were being counted at the time. These are couple months out of date, but I don't think these top numbers are budging very much right now. Note that these sales numbers are the average for all volumes sold, not the total number of volumes. For example, if the first volume of something sold 200 units, and the second sold 100, the number provided would be 150. Sales of discs measure the popularity of late-night anime, AKA most of the anime we watch.

1. The World of Golden Eggs (2005): 139,252 units average. World of Golden Eggs is a weird short about...eggs.2. Neon Genesis Evangelion (1995): 111,559 units average. I think most of us are familiar with this.3. The World of Golden Eggs 2 (2006): 100,458 units average. I guess the Japanese like their eggs.4. Bakemonogatari (2009): 78,671 units average. Bakemonogatari is the best-selling full-length anime of the 21st century.5. Puella Magi Madoka Magica (2011): 71,056 units average. The inspiring true story of how the studio that made the best-selling anime of the 21st century...also made the second-best-selling anime of the 21st century. Only they made way more money on this one cuz they own more of the rights to it.6. Gundam SEED Destiny (2004): 68,732 units average. You know that Gundam nobody liked, that had that second season people liked even less? Yeah, that's this.7. Usavich (2006): 61,633 units average. I don't even know about this one, except it's a short.8. Nisemonogatari (2012): 60,580 units average. Studio Shaft, rakin' in dat cash.9. Gundam SEED (2002): 58,589 units average. How does a second season even outsell a first season? How does that even happen?10. Nekomonogatari BLACK (2013): 56,938 units average. Okay, Shaft, now you're just fucking with us.11. Attack on Titan (2013): 53,877 units average. The inspiring story about a man who couldn't draw, deciding to draw anyway, thus spawning the anime that defined a generation.12. Usavich 2 (2007): 53,230 units average. It won't go awaaaaaaay...13. Fate/Zero (2011): 52,133 units average. The inspiring story of the worst story ever written, getting a prequel which was really fantastic...because it was written by a completely different person. And then it got animated.14. Usavich 3 (2008): 52,016 units average. I just...I don't even have anything to say anymore.15. Macross Frontier (2008): 46,147 units average. Ah, Macross. That one anime about...space...or something...yeah I know nothing about Macross.16. Fate/Zero 2 (2012): 45,804 units average. Split-cour anime: an innovation for a modern era.17. Code Geass (2006): 45,367 units average. WHOOOOOOOOOOOOO!!!18. Monogatari Series Second Season (2013): 45,005 units average. Monogatari Series Second Season, the third season of the Monogatari Series. 3.5th? Whatever.19. Usavich 4 (2011): 44,544 units average. AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA20. K-On! (2009): 43,884 units average. The inspiring story of a studio taking a not-very-good manga and completely rewriting it however they wanted to make a better anime. Which people outside of Japan don't like anyway. But still. It made a lot of money.

Ever notice how there's some anime and manga that are institutions in Japan but virtually unknown here in the West? Like how Sazae-san might be the most viewed anime of all time in Japan but most Western otaku have never heard of it or the comic strip it's based on. And how about Gegege no Kitaro? Not very famous here either.

Anyone know any other manga and anime that are huge in Japan but obscure here?